Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
van hanh » van thanh, ban hanh, van anh
cua viet » ca viet, hoa viet, cua vat
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
tang ma » mang may, tang van
va hanh » va thanh, va danh, ban hanh
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((nang xa) or (tang ma)) hoi. hieu van pham duc ((va hanh) or (van hanh)) vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang xa) OR (tang ma)) hoi. hieu van pham duc ((va hanh) OR (van hanh)) vi cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) or (tang ma)) hoi. hieu van pham duc ((va hanh) or (van hanh)) vi cua viet*.